U.S. patent number 11,298,001 [Application Number 16/362,351] was granted by the patent office on 2022-04-12 for calibration tool for rotating endoscope.
This patent grant is currently assigned to Canon U.S.A., Inc.. The grantee listed for this patent is Canon USA Inc.. Invention is credited to Jacob Schieffelin Brauer, Anderson Thi Mach, Tzu-Yu Wu.
![](/patent/grant/11298001/US11298001-20220412-D00000.png)
![](/patent/grant/11298001/US11298001-20220412-D00001.png)
![](/patent/grant/11298001/US11298001-20220412-D00002.png)
![](/patent/grant/11298001/US11298001-20220412-D00003.png)
![](/patent/grant/11298001/US11298001-20220412-D00004.png)
![](/patent/grant/11298001/US11298001-20220412-D00005.png)
![](/patent/grant/11298001/US11298001-20220412-D00006.png)
![](/patent/grant/11298001/US11298001-20220412-D00007.png)
![](/patent/grant/11298001/US11298001-20220412-D00008.png)
![](/patent/grant/11298001/US11298001-20220412-M00001.png)
![](/patent/grant/11298001/US11298001-20220412-M00002.png)
View All Diagrams
United States Patent |
11,298,001 |
Mach , et al. |
April 12, 2022 |
Calibration tool for rotating endoscope
Abstract
Apparatus and methods for correcting distortion of a spectrally
encoded endoscopy ("SEE"), more specifically, the subject
disclosure provides a calibration tool calibrating a rotating
spectrally encoded endoscope, which may be reused to recalibrate
the endoscope throughout the lifecycle, and which may further act
to protect the endoscope during packaging, shipping and
handling.
Inventors: |
Mach; Anderson Thi (Cambridge,
MA), Wu; Tzu-Yu (Malden, MA), Brauer; Jacob
Schieffelin (Cambridge, MA) |
Applicant: |
Name |
City |
State |
Country |
Type |
Canon USA Inc. |
Melville |
NY |
US |
|
|
Assignee: |
Canon U.S.A., Inc. (Melville,
NY)
|
Family
ID: |
68056580 |
Appl.
No.: |
16/362,351 |
Filed: |
March 22, 2019 |
Prior Publication Data
|
|
|
|
Document
Identifier |
Publication Date |
|
US 20190298154 A1 |
Oct 3, 2019 |
|
Related U.S. Patent Documents
|
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
|
62650155 |
Mar 29, 2018 |
|
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G02B
23/2476 (20130101); A61B 1/00172 (20130101); G02B
23/24 (20130101); G06T 7/80 (20170101); A61B
1/00096 (20130101); A61B 1/00057 (20130101); A61B
1/0638 (20130101); A61B 1/0014 (20130101); A61B
1/00137 (20130101); G06T 2207/10024 (20130101); G06T
2207/10068 (20130101) |
Current International
Class: |
A61B
1/00 (20060101); G06T 7/80 (20170101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
|
|
|
|
|
|
|
2010-515947 |
|
May 2010 |
|
JP |
|
2011110157 |
|
Jun 2011 |
|
JP |
|
2017/117203 |
|
Jul 2017 |
|
WO |
|
Other References
Web, Reveal Distal Attachment Cap, US Endoscopy, 3 pages,
http://www.usendoscopy.com/Products/Reveal-distal-attachment-cap.aspx.
cited by applicant .
Wenbo Wang, et al., Disposable sheath that facilitates endoscopic
Raman spectroscopy, Web, Journal of Biomedical Optics, vol. 21,
Issue 2,
http://biomedicaloptics.spiedigitallibrary.org/article.aspx?articleid=248-
8934, Feb. 17, 2017. cited by applicant .
Joshua Gafford, et al., Snap-On Robotic Wrist Module for Enhanced
Dexterity in Endoscopic Surgery, May 16, 2016, pp. 1-8, 2016 IEEE
International Conference on Robotics and Automation (ICRA), May
16-21, 2016, IEEE, Stockholm, Sweden. cited by applicant.
|
Primary Examiner: Leubecker; John P
Attorney, Agent or Firm: Canon U.S.A., Inc. IP Division
Parent Case Text
CROSS REFERENCE TO RELATED PATENT APPLICATIONS
This application claims priority from U.S. Provisional Patent
Application No. 62/650,155 filed on Mar. 29, 2018, in the United
States Patent and Trademark Office, the disclosure of which is
incorporated by reference herein in its entirety.
Claims
The invention claimed is:
1. A method for calibrating a rotating SEE, the method comprising:
providing a calibration apparatus comprising: a body configured to
encompass at least a portion of a SEE; a bottomed surface affixed
to a distal end of the body; and a calibration chart configured on
an inside wall portion of the apparatus, wherein the apparatus has
an open end, opposite the bottomed surface, wherein the open end is
configured to receive the at least a portion of the SEE, and the
SEE is a rotating SEE, scanning the calibration chart with a SEE
spectral line to obtain an image; determining a sign of a
tangential shift of the spectral line based on a slope of at least
one of the radial lines of the first image in a polar coordinate;
computing a magnitude of the tangential shift based on at least one
of the radial lines of the first image in either a polar coordinate
or a Cartesian coordinate; determining a sign of a radial shift of
the spectral line based on whether the slope has a turning point or
not; computing a magnitude of the radial shift by measuring a
location of the turning point if the radial shift is determined to
be negative; scanning the calibration chart with the SEE spectral
line to obtain a second image if the radial shift is determined to
be positive; computing the magnitude of the radial shift based on
the magnitude of the tangential shift and a radius of the circle;
and applying the tangential shift and the radial shift for a
corrected calibration.
2. The method of claim 1, wherein the calibration apparatus further
comprising an attachment element configured to rigidly and
removably attach the apparatus to the SEE.
3. The method of claim 1, wherein the calibration apparatus is
configured to further extend onto a sheath of the SEE.
4. The method of claim 1, wherein the calibration apparatus is
configured for repeated attachment and removal from the at least a
portion of the SEE.
5. The method of claim 1, wherein the calibration chart of the
calibration apparatus is positioned at a predetermined distance
from the SEE.
6. The method of claim 1, wherein the bottomed surface of the
calibration apparatus is configured to be ruptured by the SEE,
allowing the SEE to protrude through the bottomed surface of the
apparatus.
7. The method of claim 1, wherein the calibration apparatus further
comprising a second calibration chart configured on an inside wall
portion of the apparatus.
8. The method of claim 1, wherein the bottomed surface of the
calibration apparatus is configured to be rotatable or pivotable,
allowing for rearrangement of the bottomed surface with respect to
the SEE.
9. The method of claim 1, wherein the calibration chart in the body
has a diameter larger than a diameter of the SEE.
Description
FIELD OF THE DISCLOSURE
The present disclosure relates generally to apparatus and methods
for calibrating a scanning electron endoscope ("SEE"), and more
particularly, to calibrating a rotating SEE.
BACKGROUND OF THE DISCLOSURE
Medical probes have the ability to provide images from inside a
patient's body. Considering the potential harm capable to the human
body caused by the insertion of a foreign object, it is preferable
that the probe be as small as possible. Additionally, the ability
to provide images within small pathways such as vessels, ducts,
incisions, gaps and cavities dictates the use of a small probe
One particularly useful medical probe is the SEE, which is a
miniature endoscope that can conduct high-definition imaging
through a sub-mm diameter probe. In operation, light from a light
guiding component found in the SEE probe, (single mode fiber
("SMF") usually for better resolution) is first coupled into a
coreless fiber and then into a Gradient Index ("GRIN") lens and
then the light is diffracted through a prism with a grating. The
diffracted light is scanned across the sample to be analyzed. Light
reflected by the sample is captured by a detection fiber and imaged
for viewing.
As an example of a calibration technique for an endoscope that
scans an optical fiber and acquires an image, Japanese Patent
Application Laid-Open Publication No. 2010-515947 discloses a
scanning beam apparatus. The Japanese Patent above discloses a
method for calibrating a scanning beam apparatus, the method
including acquiring an image of a calibration pattern using the
scanning beam apparatus, comparing the acquired image with a
representation of the calibration pattern and calibrating the
scanning beam apparatus based on the comparison, in order to
improve distortion of the acquired image by enhancing the accuracy
of estimation of the position of an illumination spot for each
pixel point in a scan pattern.
In recent years SEE have advanced to allow for a greater field of
vision for the endoscope, while retaining the diminutive size
leading to less evasive imaging and surgical procedures. As
provided in WO publication No. 2017/117203, the use of a rotating
light dispersion fiber in the SEE allows for varying angles of
incidents of light from the light dispersion fiber, which relays to
a greater field of vision captured by the detection fiber.
Specifically, the polychromatic light emanating from this rotating
SEE probe is spectrally dispersed and projected in such a way that
each color (wavelength) illuminates a different location on the
tissue along the dispersive line. Reflected light from the tissue
can be collected and decoded by a spectrometer to form a line of
image, with each pixel of the line image corresponding to the
specific wavelength of illumination. Spatial information in the
other dimension perpendicular to the dispersive line is obtained by
rotating the light dispersion fiber using a motor. For the forward
viewing SEE imaging, spatial information in the other dimension
perpendicular to the dispersive line is obtained by rotating the
probe using a rotary motor such that target is circularly
scanned.
Due to various environmental variables, manufacturing variables,
imperfect electronics, the sensitivity of the scanning fiber
apparatus, and/or other factors, calibration of a SEE is typically
required for improved and/or consistent imaging. The added
complications of having a rotating probe, as provided in WO
publication No. 2017/117203, further calls for calibration and
method intended for a rotating SEE.
SUMMARY
The subject disclosure provides apparatus and methods for
correcting distortion of a rotating spectrally encoded endoscopy
image. More specifically, the subject disclosure provides an
apparatus for calibrating a scanning electron endoscope ("SEE"),
the apparatus comprising a body configured to encompass at least a
portion of a SEE, as well as a bottomed surface affixed to a distal
end of the body; and a calibration chart configured on an inside
wall portion of the apparatus, wherein the apparatus has an open
end, opposite the bottomed surface, wherein the open end is
configured to receive the at least a portion of the SEE, and the
SEE is a rotating SEE.
In various embodiments, the apparatus further comprising an
attachment element configured to rigidly and removably attach the
apparatus to the SEE. Furthermore, the apparatus is configured
wherein the body of the apparatus is configured to further extend
onto a sheath of the SEE.
In another embodiment, the apparatus is configured for repeated
attachment and removal from the at least a portion of the SEE.
In further embodiments of the apparatus, the calibration chart is
positioned at a predetermined distance from the SEE.
In yet another embodiment, the apparatus has the bottomed surface
configured to be ruptured by the SEE, allowing the SEE to protrude
through the bottomed surface of the apparatus. In further
embodiment, the inside wall portion may be an inside wall portion
of the bottomed surface. Furthermore, the inside wall portion may
be an inside wall portion of the body.
In other embodiment of the subject apparatus, a second calibration
chart configured on an inside wall portion of the apparatus is
utilized.
Further embodiment devise the bottomed surface to be configured to
be rotatable or pivotable, allowing for rearrangement of the
bottomed surface with respect to the SEE.
In additional embodiment, the apparatus further comprising an
intermediate surface configured in the apparatus, wherein the
intermediate surface contains at least one calibration chart.
The subject innovation further details a method for calibrating a
rotating SEE, the method comprising: providing a calibration
apparatus comprising: a body configured to encompass at least a
portion of a SEE; a bottomed surface affixed to a distal end of the
body; and a calibration chart configured on an inside wall portion
of the apparatus, wherein the apparatus has an open end, opposite
the bottomed surface, wherein the open end is configured to receive
the at least a portion of the SEE, and the SEE is a rotating SEE,
the method including: scanning the calibration chart with an SEE
spectral line to obtain an image; determining a sign of a
tangential shift of the spectral line based on a slope of at least
one of the radial lines of the first image in a polar coordinate;
computing a magnitude of the tangential shift based on at least one
of the radial lines of the first image in either a polar coordinate
or a Cartesian coordinate; determining a sign of a radial shift of
the spectral line based on whether the slope has a turning point or
not; computing a magnitude of the radial shift by measuring a
location of the turning point if the radial shift is determined to
be negative; scanning the calibration chart with the SEE spectral
line to obtain a second image if the radial shift is determined to
be positive; computing the magnitude of the radial shift based on
the magnitude of the tangential shift and a radius of the circle;
and applying the tangential shift and the radial shift for a
corrected calibration.
In various embodiment, the subject method further provides, wherein
the calibration apparatus further comprising an attachment element
configured to rigidly and removably attach the apparatus to the
SEE.
In yet additional embodiment, the subject method teaches the
calibration apparatus to be configured to further extend onto a
sheath of the SEE.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1(a) provides an illustration of an exemplary SEE probe
including a calibration tool, according to one or more embodiment
of the subject disclosure.
FIG. 1(b) provides an image of an exemplary SEE probe including a
calibration tool being removed, according to one or more embodiment
of the subject disclosure.
FIG. 2 is a flow chart illustrating a method for calibrating a SEE
probe incorporating a calibration tool, according to one or more
embodiment of the subject disclosure.
FIG. 3(a) depicts a SEE probe including an exemplary calibration
tool, according to one or more embodiment of the subject
disclosure.
FIG. 3(b) portrays a SEE probe including an exemplary calibration
tool, according to one or more embodiment of the subject
disclosure.
FIG. 3(c) illustrates a SEE probe including an exemplary
calibration tool, according to one or more embodiment of the
subject disclosure.
FIG. 3(d) portrays a SEE probe including an exemplary calibration
tool, according to one or more embodiment of the subject
disclosure.
FIGS. 4A-4D provide various SEE probes fitted with exemplary
calibration tools, according to one or more embodiment of the
subject disclosure.
FIGS. 5(a) and 5(b) depict a SEE probe including an exemplary
calibration tool, according to one or more embodiment of the
subject disclosure.
FIGS. 6(a)-6(c) provide an exemplary calibration tool, capable of
removal and reassertion, according to one or more embodiment of the
subject disclosure.
FIGS. 7(a) and 7(c) illustrate an exemplary calibration tool,
according to one or more embodiment of the subject disclosure.
FIGS. 8(a) through 8(h) portrays various calibration charts, which
may be utilized in an exemplary calibration tool, according to one
or more embodiment of the subject disclosure.
FIGS. 9(a) and 9(b) provide various SEE probes fitted with an
exemplary calibration tool, according to one or more embodiment of
the subject disclosure.
FIGS. 10(a)-10(c) provide an exemplary calibration tool, utilizing
multiple stages of calibration, according to one or more embodiment
of the subject disclosure.
FIG. 11 illustrates a SEE probes fitted with an exemplary
calibration tool having multiple calibration wells, according to
one or more embodiment of the subject disclosure.
FIG. 12 portrays a SEE probes fitted with an exemplary calibration
tool having multiple calibration wells, according to one or more
embodiment of the subject disclosure.
FIGS. 13A and 13B provide a SEE probes fitted with an exemplary
calibration tool having multiple calibration wells, with 13A
depicting a side view and 13B providing a top view, according to
one or more embodiment of the subject disclosure.
FIGS. 14(a) and 14(b) provide exemplary calibration tools,
according to one or more embodiment of the subject disclosure.
In addition, FIG. 15 is a flow chart providing a method for
calibrating a SEE probe, according to one or more embodiment of the
subject disclosure.
DETAILED DESCRIPTION
Further objects, features and advantages of the present disclosure
will become apparent from the following detailed description when
taken in conjunction with the accompanying figures showing
illustrative embodiments of the present disclosure.
FIGS. 1(a) and 1(b) provide illustrations of an exemplary SEE probe
including a calibration tool, according to one or more embodiment
of the subject disclosure. In FIG. 1(a), the calibration tool 10 to
configured to resemble a cylindrical cap, to be fitted to the SEE
12, while FIG. 1(b) depict the calibration tool 10 being removed
from the SEE 12, preferably after calibration has been completed.
The calibration tool 10 comprises a distal end 14, which has a
bottomed cylindrical surface 16, and hollow cylindrical body 18
which is configured perpendicular to the bottomed cylindrical
surface 16, and a proximal end 20 which is gapped for accepting the
SEE 12. The bottomed cylindrical surface 16 is configured to accept
a calibration chart 22, which is used for calibrating the SEE 12
(as detailed below). The calibration tool 10 is configured such
that the inner calibration chart 22 is positioned at a
predetermined distance with respect to the tip 24 of the SEE 12.
The calibration is performed by irradiating light onto the
calibration chart 22 and processing the image data of the inner
surface of the cap. In various embodiments, an illumination source
is configured to provide the irradiating light, with a detection
fiber being incorporated to capture the reflected light and send
the information to a spectrometer for processing the image
data.
In various embodiments, the calibration tool 10 may be removable
affixed to the SEE 12 by pressure fitment, snap fitment,
rotationally coupled, clamped, buttoned, threaded, screwed, glued
on, taped, or any other appropriate fastening means known in the
art.
In addition, the calibration chart 22 may be configured to be water
proof and/or solvent proof, allowing for cleaning and exposure of
the calibration tool 10 to water and other elements.
The SEE 12 may be prepackaged with a calibration tool 10, for ease
of operation and calibration. In this instance, the user may
perform a re-calibration of the SEE 12 with the calibration tool 10
pre-fitted to the SEE 12. The user initiates the automatic
calibration through the software which operates the SEE 12 within
the calibration tool 10 (discussed in detail below). Upon
completion of calibration, the user removes the calibration tool 10
and begins intended use of the SEE 12.
When the user is done operating the SEE 12, the user properly
disposes of the SEE 12 and calibration tool 10. Alternatively, the
SEE 12 may be recapped with the calibration tool 10 to enclose the
SEE 12, which has been exposed to tissue or bodily fluids.
Furthermore, and intended for non-disposable SEE's 12, the SEE 12
and calibration tool 10 may be re-sterilized individually, then the
SEE 12 is re-capped with the calibration tool 10 and stored for
future use.
FIG. 2 is a flow chart illustrating a method for calibrating a SEE
probe incorporating a calibration tool, according to one or more
embodiment of the subject disclosure. As provided, the SEE 12 is
assembled with the calibration tool 10 fixed to the SEE 12 by the
manufacturer, and a manufacturer initiated calibration is
performed. The SEE 12 and accompanying calibration tool 10 are
sterile packed for shipment to an end user. The end user removes
the combined SEE 12 and calibration tool 10 from the sterilized
packaging, and recalibrates the SEE 12, which may have been
unsettled during shipping and/or handling. After recalibration, the
end user removes the calibration tool 10, and operates the SEE 12
as intended.
FIG. 3(a) depicts a SEE probe including an exemplary calibration
tool, according to one or more embodiment of the subject
disclosure. In this embodiment, the SEE 12 may be covered by a
rigid calibration tool 10, which would enhance protection of the
SEE 12 tip 24. The calibration tool 10 may be attached to the SEE
12, at or near the proximal end of the SEE 12, as illustrated by
the attachment element 26. The attachment element 26 or mechanical
features of the calibration tool 10 may align the SEE 12 axially
centered to the calibration chart 22, thus positioning the SEE 12
and calibration tool 10 for accurate and repeatable calibration.
The rigid calibration tool 10 may also be useful in protecting the
tip 24 in packaging, shipping, storage and/or handling of the SEE
12.
In addition, the calibration tool 10 may be utilized to prevent
dust, particles, physical contamination from accumulating on the
distal imaging lens of the SEE 12, or window of the SEE 12. If the
SEE 12 scope is flexible, the calibration tool 10 can cover a
length of the flexible sheath 28 to protect from bending or kinking
as well (See FIG. 3(b)).
FIGS. 3(a) through 3(d) portray a SEE probe including an exemplary
calibration tool, according to one or more embodiment of the
subject disclosure. FIGS. 3(a) and 3(c) incorporate a calibration
tool 10 configured to cover a shorter portion of the SEE 12, with
FIG. 3(c) employing the attachment element 26 designed to better
protect the tip 24 of the SEE 12. FIGS. 3(b) and 3(d) detail a
calibration tool 10 configured to cover a longer portion of the SEE
12, which may include the sheath 28 portion of the SEE 12 as well.
The sheath 28, may be flexible or rigid, with the calibration tool
10 designed to offer greater protection to the sheath 28 in
addition to the See 12 tip 24. FIG. 3(d) also employs the
attachment element 26 designed to better protect the tip 24 and
sheath 28 of the SEE 12.
FIG. 4 provides various SEE probes fitted with exemplary
calibration tools, according to one or more embodiment of the
subject disclosure. In various instances, the SEE 12 may be
utilized as a sub-system of a larger medical device. As provided in
FIG. 4, the SEE 12 tips 24 of these sub-systems may be fitted by
the subject calibration tool 10, which would be fitted to the
distal end of the SEE 12.
FIGS. 5(a) and 5(b) depict a SEE probe including an exemplary
calibration tool having a break-through cylindrical surface 16,
according to one or more embodiment of the subject disclosure. In
this embodiment, the subject calibration tool 10 incorporates a
break-through bottomed cylindrical surface 16, wherein the
calibration chart 22 is also broken-through once the SEE 12 has
been calibrated. As provided in FIG. 5(a), the calibration tool 10
is fitted to the SEE 12, and calibration is conducted. Once
calibration is completed, the calibration tool 10 is forcibly urged
parallel to and towards the SEE 12, thus rupturing the bottomed
cylindrical surface 16, and exposing the SEE 12 tip 24 for use, as
provided in FIG. 5(b). The calibration tool 10 in this embodiment
is intended for one-time calibration use only.
FIGS. 6(a)-6(c) provide an exemplary calibration tool, capable of
removal and reassertion, according to one or more embodiment of the
subject disclosure. In the embodiment provided in FIGS. 6(a)
through 6(c), the calibration tool 10 is intended to be used
repeatedly, as the calibration tool 10, may be removed and
reasserted on the SEE 12. In this embodiment, the calibration tool
12 may be used as a safety device to cover the See 12 tip 24, after
the tip 24 has been exposed to biological fluids and/or biological
matter. In various other embodiments, the calibration tool 12 and
SEE may both be sterilized, and the calibration tool 12 may be
refitted on the SEE 12 for safe storage and future use. In an
embodiment, the SEE may be designed for single use, such that after
exposure to biological fluids, the SEE may be discarded. In such
case, the SEE may also be recapped, thus ensuring the potentially
biohazard material on the SEE is isolated for proper handling and
disposal.
FIGS. 7(a) and 7(b) illustrate an exemplary calibration tool,
according to one or more embodiment of the subject disclosure. In
this embodiment, the calibration tool 10 is fitted with a bottomed
cylindrical surface 16 capable of being rotated and/or pivoted. The
rotating and/or pivoting is configured to allow the SEE 12 tip 24
to advance beyond and through the calibration tool 10, as seen in
FIG. 7(b), without damaging the bottomed cylindrical surface 16 of
the calibration tool 10, as well as the calibration chart 24. In
various embodiments, the rotating and/or pivoting bottomed
cylindrical surface 16 may consist of a shutter-type element, one
or more pivot attachments, or derivatives thereof. As seen in FIGS.
7(a) through 7(c), calibration is accomplished with the calibration
tool 10 configured on the SEE 12, wherein upon completion of
calibration, the calibration tool 10 may be urged parallel to and
towards the SEE 12, enacting the rotating and/or pivoting of the
bottomed cylindrical surface 16, and exposing the SEE 12 tip 24 for
use. Finally, FIG. 7(c) depicts how the calibration tool 10 may be
returned to a position of protecting the tip 24, by urging the
calibration tool 10 parallel to and away from the SEE 12, thus
enacting the rotating and/or pivoting of the bottomed cylindrical
surface 16 to conceal the SEE 12 and tip 24 from the
environment.
In various embodiments, the rotating and/or pivoting bottomed
cylindrical surface 16 may be configured for one-time use, wherein
the bottomed cylindrical surface 16 is locked once the calibration
tool 10 is urged parallel to and away from the SEE 12, thus
enacting the rotating and/or pivoting of the bottomed cylindrical
surface 16 to a concealed position. In another embodiment, the
rotating and/or pivoting bottomed cylindrical surface 16 may be
configured for repeated use, allowing an end user to repeatedly
expose and conceal the tip 24 by enacting the rotating and/or
pivoting of the bottomed cylindrical surface 16. In addition, for
repeated use of the pivoting bottomed cylindrical surface 16, the
SEE 12 and calibration tool 10 may be sterilized between uses to
ensure consistency and safety of the calibration tool 10.
FIGS. 8(a)-8(h) portray various calibration charts, which may be
utilized in an exemplary calibration tool, according to one or more
embodiment of the subject disclosure. The various examples of
calibration charts 22 provided in FIGS. 8(a) through 8(h) may be
used independently or in combination in the calibration tool 10. As
stated prior, calibration can be accomplished by scanning a
calibration chart 22 found at the distal end 14 of the calibration
tool 10. The chart 22 can be a combination of various charts for a
single chart to allow for various calibrations. Multiple
calibration tools 10 with different charts 22 can be used to
perform multiple individual calibrations of a single SEE 12.
Forward view SEE's visualize calibration charts 22 at the distal
end 14 of the calibration tool 10, while side-view SEE's will
visualize calibration charts 22 on the cylindrical body 18 of the
calibration tool 10. Various calibration charts 22 may include a
color wheel, gradients, stepped chart, variations thereof,
combinations of charts, and alternatives thereof.
By way of example, FIG. 9(a) illustrates a forward view SEE 12
visualizing calibration charts 22 at the distal end 14 of the
calibration tool 10. FIG. 9(b) denotes a side-view SEE 12 which is
configured to visualize calibration charts 22 on the cylindrical
body 18 of the calibration tool 10. Alternatively, combinations of
side-view and forward view SEE's may merit a calibration tool 10
having both side-view and forward view calibration charts.
FIGS. 10(a)-10(c) provide an exemplary calibration tool, utilizing
multiple stages of calibration, according to one or more embodiment
of the subject disclosure. As provided in FIGS. 10(a) through
10(c), a calibration tool 10, may incorporate one or more
intermediate surface(s) 30 configured in the cylindrical
calibration tool 10, wherein each intermediate surface 30 in
situated about perpendicular to the cylindrical body 18 of the
calibration tool 10, with each intermediate surface 30 having one
or more calibration chart(s) 22 for calibrating the SEE 12. Each
intermediate surface 30 may be configured to allow the SEE 12 to
pierce through the intermediate surface 30 by forcibly urging the
calibration tool 10 parallel to and towards the SEE 12, thus
advancing the SEE 12 to the following intermediate surface 30
and/or bottomed cylindrical surface 16. In one embodiment, the one
or more intermediate surface(s) 30 may be capable of being rotated
and/or pivoted. The rotating and/or pivoting is configured to allow
the SEE 12 tip 24 to advance beyond and through the calibration
tool 10 without damaging the intermediate surface 30. In various
embodiments, the rotating and/or pivoting intermediate surface 30
may consist of a shutter-type element, one or more pivot
attachments, or derivatives thereof. As seen in FIGS. 10(a) through
10(c), calibration is accomplished with the calibration tool 10
configured on the SEE 12, wherein upon completion of calibration,
the calibration tool 10 may be urged parallel to and towards the
SEE 12, enacting the rotating and/or pivoting of the intermediate
surface 30, and exposing the SEE 12 tip 24 to a secondary and/or
tertiary intermediate surface 30 for additional calibration. Upon
completion of all stages of calibration conducted by each
intermediate surface 30 and bottomed cylindrical surface 16, the
SEE 12 is now properly calibrated for use by the end user. Each
intermediate surface 30 may have one or more calibration chart(s)
22 for calibrating the SEE 12.
In yet another embodiment of the calibration tool 10, illustrated
in FIG. 11, a SEE 12 probe employs an exemplary calibration tool 10
having multiple calibration wells, according to one or more
embodiment of the subject disclosure. Each well 32 contains one or
more calibration chart(s) 22 for calibrating the SEE 12.
Alternatively, FIGS. 12 and 13 depicts a calibration tool 10,
wherein a single well 32 in employed containing a slider 34
configured with multiple slots 36, each having a calibration chart
22. After calibration with a first calibration chart 22 in a first
slot 36(a) is performed, the slider 34 is positioned for
calibration of additional calibration charts in additional slots
36(b), 36(c) and 36(d). It is contemplated that additional
calibration charts may be incorporated into each slot 36, as well
as the use of additional slots 36 in the slider 34. Although
longitudinal (FIG. 12) and rotating (FIG. 13) slider 34
configurations have been illustrated, it is contemplated herein
that any appropriate and alternative configuration for a slider is
within the scope of the present disclosure.
As provided in FIGS. 14(a) and 14(b), the calibration tool 10 may
incorporate a visual indicator 38 for identifying the imaging
orientation of the calibration tool 10, and associated SEE, when
attached to the calibration tool 10. Through label markings or
design features, the calibration tool 10 is used to designate SEE
12 view orientations such as `top` or `upright` so that the user
can easily identify how to hold and manipulate the SEE 12.
Calibration for SEE
Below are various methods for calibration and/or correction of
distortion for a SEE, which would be used in conjunction with the
subject calibration tool, disclosed herein. A first reference
pattern having a plurality of radial lines is scanned with an SEE
spectral line to obtain a first image. A sign of a tangential shift
of the spectral line is determined based on a slope of at least one
of the radial lines of the first image in a polar coordinate. A
magnitude of the tangential shift is computed based on at least one
of the radial lines of the first image in either a polar coordinate
or a Cartesian coordinate. A sign of a radial shift of the spectral
line is determined based on whether the slope has a turning point
or not. A magnitude of the radial shift is determined by measuring
a location of the turning point if the radial shift is determined
to be negative. A second reference pattern comprising at least a
circle is scanned to obtain a second image if the radial shift is
determined to be positive. The magnitude of the radial shift is
computed based on the magnitude of the tangential shift and a
radius of the circle. The tangential shift and the radial shift are
then applied for correcting distortion.
By way of example, the step of computing the magnitude of the
tangential shift comprises determining a shift of the radial line
of the first image from an original position in the Cartesian
coordinate. Alternatively, the step of computing the magnitude of
the tangential shift may comprise selecting at least three radial
lines with the spectral line that are equally spaced from each
other with an angle and each intersecting with the spectral line at
an intersection point and computing the magnitude of the tangential
shift based on the angle, a first distance between the intersecting
points of a first and a second of the at least three radial lines,
and a second distance between the intersecting points of the second
and a third of the intersecting points.
The step of computing a magnitude of the radial shift may further
include measuring the location of the turning point by determining
where a second derivative of the radial line is zero if the radial
shift is determined to be negative. The method may include, wherein
when the sign of the radius shift is positive, the magnitude of the
radial shift is computed by the relations: R.sub.r= {square root
over (R.sub.0.sup.2-R.sub.t.sup.2)}-d where R.sub.r is the radial
shift, R.sub.t is the tangential shift, R.sub.o is the radius of
the circle, and d is the distance between the circle and a target
radius. When the sign of the radius shift is negative, the
magnitude of the radial shift is computed by the relations:
R.sub.r=d- {square root over (R.sub.0.sup.2-R.sub.t.sup.2)} where
R.sub.r is the radial shift, R.sub.t is the tangential shift,
R.sub.o is the radius of the circle, and d is the distance between
the circle and a target radius.
The step of applying the tangential shift and the radial shift for
correcting distortion further comprises applying the tangential
shift and the radial shift to determine actual location (x', y') of
the radial lines represented by: x'=.rho. cos .theta.-R.sub.t sin
.theta.+R.sub.r cos .theta. y'=.rho. sin .theta.+R.sub.t cos
.theta.+R.sub.r sin .theta. where .rho. is pixel index along the
SEE spectral line, .theta. is rotation angle of the SEE spectral
line.
An additional method for correcting distortion of a spectrally
encoded endoscopy (SEE) image includes the following steps. A first
reference pattern comprising a plurality of radial lines is scanned
with an SEE spectral line to obtain a first image. A sign of a
tangential shift of the spectral line is determined based on a
slope of at least one of the radial lines of the first image in a
polar coordinate. A second reference pattern comprising at least
two concentric circles is scanned with the SEE spectral line to
obtain a second image, the two concentric circles having a first
radius and a second radius, respectively. The magnitude of the
tangential shift and a magnitude of a radial shift of the spectral
line are scanned by measuring locations of the spectral line
corresponding to the two concentric circles in the polar
coordinate. The tangential shift and the radial shift are applied
for correcting distortion.
The step of computing the magnitude of the tangential shift may
comprise determining a shift of the radial line of the first image
from an original position in the Cartesian coordinate. The radial
shift may be calculated based on the relationship:
.times. ##EQU00001## and the tangential shift is calculated based
on the relationship:
.times. ##EQU00002## The step of applying the tangential shift and
the radial shift for correcting distortion further comprises
applying the tangential shift and the radial shift to determine
actual location (x', y') of the radial lines represented by:
x'=.rho. cos .theta.-R.sub.t sin .theta.+R.sub.r cos .theta.
y'=.rho. sin .theta.+R.sub.t cos .theta.+R.sub.r sin .theta. where
.rho. is pixel index along the SEE spectral line, .theta. is
rotation angle of the SEE spectral line.
In another embodiment, a first reference pattern comprising a
plurality of radial lines is scanned with an SEE spectral line to
obtain a first image. A sign of a tangential shift of the spectral
line is determined based on a slope of at least one of the radial
lines of the first image in a polar coordinate. A magnitude of the
tangential shift is determined based on a shift of at least one of
the plurality of the radial lines on a Cartesian coordinate or
based on at least three angularly equally radial lines included in
the plurality of radial lines scanned by the SEE spectral line. The
magnitude of the tangential shift is computed based on the a shift
of at least one of the radial lines or based on at least three
angularly equally spaced radial lines included in the plurality of
radial lines. A second reference pattern comprising at least two
concentric circles is scanned with the SEE spectral line to obtain
a second image, the two concentric circles having a first radius
and a second radius, respectively. A ratio of the second radius to
the first radius is provided. A radial shift of the spectral lines
is computed based on the tangential shift and the ratio; and the
tangential shift and the radial shift are applied for correcting
distortion.
The step of computing the magnitude of the tangential shift may
comprise determining a shift of the radial line of the first image
from an original position in the Cartesian coordinate. The step of
computing the magnitude of the tangential shift may also comprise
selecting at least three radial lines that are equally spaced from
each other with an angle and each intersecting with the spectral
line at an intersection point and computing the magnitude of the
tangential shift based on the angle, a first distance between the
intersecting points of a first and a second of the at least three
radial lines, and a second distance between the intersecting points
of the second and a third of the intersecting points.
The radial shift is calculated based on the relationship of:
.times..+-..times..function. ##EQU00003## where k is the ratio of
the second radius to the first radius. The step of applying the
tangential shift and the radial shift for correcting distortion
further comprises applying the tangential shift and the radial
shift to determine actual location (x', y') of the radial lines
represented by: x'=.rho. cos .theta.-R.sub.t sin .theta.+R.sub.r
cos .theta. y'=.rho. sin .theta.+R.sub.t cos .theta.+R.sub.r sin
.theta. where .rho. is pixel index along the SEE spectral line,
.theta. is rotation angle of the SEE spectral line.
Another method for correcting distortion of a spectrally encoded
endoscopy (SEE) image, includes, a first reference pattern
comprising a plurality of radial lines is scanned with an SEE
spectral line to obtain a first image. A sign of a tangential shift
of the spectral line is determined based on a slope of at least one
of the radial lines of the first image in a polar coordinate. A
magnitude of the tangential shift is determined based on a shift of
at least one of the plurality of the radial lines on a Cartesian
coordinate or based on at least three angularly equally radial
lines included in the plurality of radial lines scanned by the SEE
spectral line. A second reference pattern comprising at least two
concentric circles is scanned with the SEE spectral line to obtain
a second image, the two concentric circles having a first radius
and a second radius, respectively. A ratio of the second radius to
the first radius is provided. Two possible values of the magnitude
of a radial shift of the spectral lines are computed based on the
tangential shift and the ratio. One of the possible values is
selected to calculate pixel coordinate of the radial lines imaged
by the spectral line. The tangential shift and the radial shift are
applied for correcting distortion. The other of the possible values
of the magnitude of the radial shift is selected if the distortion
is not corrected by the first possible value.
* * * * *
References